Mail candling apparatus

ABSTRACT

A mail candling apparatus for feeding an envelope to photocell scanners which depending on the density of the envelope as when the envelope contains an enclosure, will reject the envelope or when the envelope is empty will pass the same for disposal and including means for rejecting the envelope when containing bulky material.

United States Patent [1 1 Green 1 MAIL CANDLING APPARATUS [76] Inventor:Rollo G. Green, Rt. 2, box 603K,

Austin, Tex. 78704 22 Filed: Aug. 25, 1972 21 Appl. No.: 283,731

[52] US. Cl. 209/111.7, 356/240 [51] Int. Cl. B07c 5/342 [58] Field ofSearch 209/DIG. 2, 111.7, 111.6;

250/219 DO, 219 TH; 356/240, 204, 205, 206

[56] References Cited UNITED STATES PATENTS 12/1969 Hooker 209/111.712/1972 Ptacek.... 209/DlG. 2 10/1964 Simjian 209/ll1.7 X

[ Mar. 26, 1974 3,589,514 6/1971 Townsend 209/111.7 3,109,100 10/1963Gecewicz 209/11 1.6 X 3,114,444 12/1963 Patzer 209/11l.6 X 3,122,2272/1964 Bookout et 31.. 209/l11.6 X 3,133,641 5/1964 Patzer 209/111.6

Primary Examiner-A1len N. Knowles [5 7] ABSTRACT A mail candlingapparatus for feeding an envelope to photocell scanners which dependingon the density of the envelope as when the envelope contains anenclosure, will reject the envelope or when the envelope is empty willpass the same for disposal and including means for rejecting theenvelope when containing bulky material.

5 Claims, 6 Drawing Figures MAIL CANDLING APPARATUS The presentinvention is concerned with a mail candling apparatus for automaticallydetecting any material left in an envelope.

The principal object of the invention is to provide an economicallyproduceable and relatively small mail candling device which can scanenvelopes of different weights and texture of paper without adjustmentto compare the density of the envelopes and rejects envelopes containingenclosure, but passes empty envelopes.

A further and important object of the invention is to provide a mailcandling device having two or more sensing circuits working together tocompare the density of material passing thereby and when any circuitdetects a difference in density, that is mail of more or less densitythan another circuit, means will be activated that will send the mailback to the operator and which sensing circuits will not be effected bydiagonal seamsof envelopes, postage stamps, black printing or the likeon the envelope.

Further objects of the invention will be in part obvious and in partpointed out in the following description of the accompanying drawings.

FIG. 1 is a perspective view of an apparatus according to the inventionwith the lid thereof being in its open position,

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1, I

FIG. 3 is a sectional view of the feeding and scanning portion of theapparatus taken on line 3-3 of FIG. 2,

FIG. 4 is an enlarged top view of the feeding and scanning portion ofthe apparatus with the lid raised and showing the manner of introducingan envelope therein.

FIG. 5 is a view similar to FIG. 4 but showing the rejection position ofan envelope with enclosure, and

FIG. 6 is an electrical diagram of the apparatus.

Referring now more particularly to the accompanying drawings in whichlike and corresponding parts will be designated by the same referencecharacters, numberal 1 generally indicates a hollow box having a flathalf-top 2 with intermediate wall 3 normal to said top and ledges 4 and5. Said box has end wall 6 with longitudinal walls 7 and 8 extendingfrom said end wall to the opposite box end wall 11 and with base wall 9extending between walls 7 and 8 for the length thereof forming a mailslot which opens at wall 6 as the entrance thereof and also in wall 1 atexit opening 10.

A hollow lid 12 is hinged by hinge 13 to wall 3 in such a manner thatsaid lid can be raised as shown in FIG. I or closedas shown in FIGS. 2and 3, with the bottom 14 of said lid being seated on ledges 4 and 5 andproviding a continuous cover for the length of said mail slot 7-9 withhalf-top 2.

Box 1 also has side walls 15 and 16, bottom 17 completing a rectangularhollow box. Upright wall 18 extends contiguous with wall 8 to bottom 17and is fastened thereto at flange 19.

A resilient roller 20 has an axle 21 with tightening nut 22 on one endand having its other end rotatable in bearing 23 attached to wall 8 sothat said roller extends laterally of and is spaced above base wall 9.

Base wall 9 has a lateral slot 24 below roller 20 in which extends asecond resilient roller 25 which has an axle 26 with tightening nut 27on one end and which axle .26 is fixedly attached to shaft 28 extendingthrough wall 18 as part of a reversible electric motor 29 connected towall 18.

Base wall 9 also has a series of openings 31 therethrough on the mailfeed-in side of rollers 20 and 25 with a further opening 31a just infront of openings 31. Further base wall 9 has a series of openings 30 onthe mail feed-out side of rollers 20 and 25 with opening 30a just beyondopenings 30.

A housing 32 suspended below base wall 9 has a series of lamp sockets 33with photo-electric cells 35 therein, supported by said housing witheach cell below one of said openings 30 and 30a. A further series ofsockets 34 are supported by said housing with photoelectric cells 36therein and each cell 36 is below one of the base wall openings 31 and31a.

Lid bottom 14 has a series of openings 37 each positioned for beingdirectly opposite an opening 30 when said lid is in its closed position.Also said lid has opening 37a, a series of openings 38 and opening 38aeach positioned for being directly opposite opening 30a, one of saidopenings 31 and opening 31a, respectively, when said lid is closed.

Lid 12 has side walls 39 and 41, top 40, end walls 42 and 42a which withbottom 14 provides a hollow lid. Partitions 43, 46 and 47 extend fromtop 40 to bottom 14 providing lamp areas.

Lamp sockets 44 are mounted in partition 43 so that lamps 45 in saidsockets are each above one of said openings 37 and 37a. Also lampsockets 48 are mounted in partition 47 so that lamps 49 in said socketsare each above one of said openings 38 and 380.

As shown in FIG. 6 each opposite pair of photocells 30 and 31 isconnected between a positive and negative supply voltage with apotentiometer, the three being in series with the potentimeter betweenthe photocells. The value of the resistance of the potentiometer ischosen so that for normal envelopes, most of the voltage drop is acrossthe resistor, so that for denser envelopes an increasing voltage dropwill appear across both photocells and this will automatically increasethe voltage change seen at the potentiometer for a given change inphotocell current, so that the increased sensitivity required isautomatically provided. The potentiometers are adjusted for zero voltageat the taps when the photocells are uniformly lighted. Potentiometeradjustments are necessary on assembly because of differences afterassembly. 'Small Zener diodes are connected to the potentiometer tapsand are biased so that a voltage of 2.5 volts higher than the tapvoltage is also available. For each of the photodiode pairs, the voltage2.5 volts over the potentiometer tap voltage is fed to a logicalinverter 50,51 or 52. The output voltage of each of said inverters isless than 0.4 when the input is greater than 2.0 volts. The output ofeach photodiode pair circuit is two voltages, the potentiometer tapvoltage and the inverter output voltage.

The three inverter output voltages are fed to one 4- input NAND gate 54and the three potentiometer tap voltages are fed to a second 4-inputNAND gate 55. The fourth input to both gates 54 and 55 is to enablevoltage generated by photocells 30a and 31a circuits. The output of each4-input NAND gate 54 or 55 is above 2.2 volts unless all four inputs ofone NAND gate 54 or 55 rises above 2.0 volts in which case the outputvoltage of that gate drops below 0.4 volts. Thus, the

.output of both 4-input NAND gates 54 and 55 is 2.2

volts, when all photocells are evenly illuminated.

The outputs of the two 4-input NAND gates are fed to a 2-input NAND gate56. When both inputs of gate 56 are above 2.0 volts, the output is below0.4 volts.

The two electronic switch circuits shown, for the reversable pullthroughmotor and the reject reverse action are conventional saturated switchingcircuits.

Photocells 30a and 31a are connected through 2- input NAND gate 53 andinverter 53a to both gates 54 and 55. Also said photocells 30a and 31aare connected to 2-input NAND gate 58 which is also connected toinverter 57.

A thickness detect switch 62 is connected in front of inverter 57.

The 4-input NAND gates specified are Texas Instruments type SN 5413which incorporate a Schmidt trigger into the same integrated circuit,which allows the outputs of these gates to be sharp switching pulseswith relatively slowly varying inputs. This feature avoids anindecisive" or jittery output which could severely stress outputelectrical and mechanical components.

The 2-input NAN D gates are type SN 5400, the inverters type 5404 andtriacs type TIC22, all of Texas Instrument. The photocells are Clairextype CLT 3160.

Box I will contain the entire mechanical and electri cal componentsshown in the drawings and, for example could be five inches high, nineinches wide and eighteen inches long. The slot 7-9 would be one inchdeep by five inches wide and eighteen inches long. 61 indicates the Onand Off switch for the circuit of FIG. 6 and lamps 45 and 49 are alsoconnected to said switch.

The apparatus is designed with two or more sensing circuits workingtogether to compare the density of the envelope it is'sensing. When anycircuit detects a difference, more or less in density than the othercircuit, the reversable motor 29 will be activated that will send theenvelope back to the operator. For example, when a check left in anenvelope passes over one circuit the density will change for one circuitthereby creating an off balance in voltage and cause the rejection ofthe envelope. The apparatus will identify any envelope dark or light intexture and reject only when something has been left in the envelope.

The arrangement of the sensing photocells 30 and 31 is a major factor inthe proper functioning of the device. Two or more photocells 30 and 31operating together must detect a change in density of an envelopepassing thereover. This will allow the diagonal seam of the envelope topass as well as a postage stamp black printing on the envelope and thelike. The check or other document left in the envelope will besufficiently wide and squared on the end with the arrangement of thephotocells 30 and 31 to effect satisfactory detec tion.

The envelope candler operates by sensing relative light transmissionacross the width of the envelope in two or more long narrow regionswhose long dimension is parallel to the leading edge of the envelope. Asthe envelope passes through the scanning regions of the lighttransmissions 37-38 and sensing photocells 30 and 31, it can, when anenclosure enters or leaves said regions, detect through the differencesin light transmissions between said regions. The sensing device issensitive only to enclosures or obstructions in envelopes such aschecks, letters and the like of predetermined width. It is not sensitiveto enclosures or obstructions of lesser width, such as stamps, seamsaddresses,

envelope lettering and the like. The sensing circuits automaticallycompensate for changes in overall transmission so that its operation isunaffected by the use of thick colored or other unusual envelopes.

If the enclosure is a coin or something folded too small to be detectedby the photocells 30 and 31, then a gauge electrically connected toswitch 62 of the circuit will detect the thickness of the enclosure andreject the envelope.

In the operation of the apparatus when envelope A is advanced to coverphotocell 31a reversable motor 29 will be turned on and will remain onwhile either photocell 3la or 30a is covered which also causes the2-input NAND gate 53 and inverter 53a to cause the candling circuit.

The candling circuits sense light transmission through the envelope A bymeans of photocells 30 and 31, which are operated in pair. Each pair ofphotocells 30 and 31 are placed at the same distance from the lower edgeof the envelope A and said photocells form two or more columns of threeor more photocells each. The two columns of candling photocells are bothparallel to the leading edge of the envelope A and are placed so thatthey are both covered as long as both photocells 30a and 31a arecovered.

When both elements of a photocell pair both columns are evenlyilluminated, both outputs of the circuit are small. If, for example, theleft photodiode 31 of FIG. 1 in the circuit is obstructed by anenclosure that has not reached the left hand photodiode 30, thepotentiometer tap voltage will go negative, pulling the input voltage ofthe inverter 50 through the Zener diode, and the output of said inverterwill go to over 2.2 volts. If, on the other hand, the left handphotodiode 30 is obstructed by an enclosure which was not detected onthe leading edge because of a folded corner of the enclosure then whenthe trailing edge of the enclosure passes the left hand photodiode 31,the potentiometer tap voltage will rise to 2.0 volts or above. Theinverter 50 output will remain lower than 0.4 volts.

If all photocells 31 are obstructed by an enclosure which has notreached the photocells 30, the output of all inverters 50, 51 and 52will go to 2.2 volts and the output of the 4-input NAND gate 54 willdrop to 0.4 volts.

Voltages going negative on the input of 4-input NAND gate 55, will notcause its output to change, but if the trailing edge of an enclosure isdetected by all photodiode pairs the potentiometer tap voltages will allrise to 2.0 volts or more, causing the output of the second 4-input NANDgate to drop to less than 0.4 volts.

Rejection of the envelope A is caused by the follow- As long as bothinputs to Z-input NAND gate 56 are high, the output is below 0.4 volts.When either input drops below 0.8 volts the output rises to 2.2 volts.When an enclosure is detected, the output of either 4- input NAND gate54 or 55 drops below 0.8 volts and the output of the 2-input NAND gate56 rises to above 2.2 volts. When the input to inverter 57 is below 0.8volts, the output is 2.2 volts, which biases transistor 63 tosaturation, so that less than 1 volt appears on the gate of triac 60,which remains off. When an enclosure B is detected, the input toinverter 57 rises above 2.2 volts, the output drops below 0.4 volts andtransistor 63 is cut off, and the 15 volt supply through the ohmresistor continuously fires the triac 60 actuating the reverse action ofthe motor 29. 2-input NAND gate 58, transistor 64 and triac 59 operatein a similar manner whenever photocells 31a or 300 are covered. Takingthe second input of Z-input NAND gate 58 from inverter 57 stops thepullthrough phase ofmotor 29 when the reverse action of said motor isactive 1 claim:

1. A mailing candling apparatus comprising a box having a slot capableof having mail passed therethrough and which slot is defined by bottom,top and side walls, a reversible motor driven means extending acrosssaid slot and capable of moving mail along, a pair of photocells exposedthrough said slot bottom with one before said driven means and one aftersaid driven means, two straight series of photocells exposed throughsaid slot bottom with each series extending laterally of said slotbetween said pair of photocells and with one series positioned beforesaid driving means and the other series positioned after said drivingmeans, means exposed through said slot top for directing light acrosssaid slot to each one of said photocells, electrical circuit connectedto said pair of photocells capable of operating said motor when mailpasses over either one of said pair of photocells, electrical meansconnecting each opposite pair of photocells of said series of photocellsas sensing circuits connected to said driving means and capable ofreversing said driving means to reject mail from said slot when onesensing circuit creates an off-balance in voltage upon passage of mailwith an enclosure therein.

2. A mail candling apparatus as claimed in claim 1 wherein said motordriven means includes a pair of su-- perposed rollers extending betweensaid slot side walls and a reversible electrical motor is operativelyconnected to one of said rollers and said electrical circuit andelectrical means.

3. A mail candling apparatus as claimed in claim 1 wherein said boxpartially provides said top wall and a lid is pivotally con-nected tosaid box and provides the remainder of said top wall when positionedacross said slot.

4. A mail candling apparatus as claimed in claim 1 wherein saidelectrical means includes a potentiometer with said two photocellsconnected thereto and between a positive and negative voltage supply inseries with said potentiometer between said photocells, Zener diodesconnected to said potentiometer taps, an inverter connected to saiddiodes, a pair of NAND gates with said inverter connected to one of saidgates and said potentiometer taps connected to the other of said gates,a further NAND gate connected to the output of said pair of NAND gatesand switching circuits connecting the output of said further gate tosaid motor driven means.

5. A mail candling apparatus as claimed in claim 4 wherein saidelectrical means includes a plurality of potentiometers with eachpotentiometer connected to and between one photocell from each seriesthereof, positive and negative voltage supplies each connected to onephotocell from each series thereof and in series with their respectivepotentiometer, Zener diodes connected to said potentiometer taps,inverters each connected t9t he diodes of one potentiometer, a pair of4- input NAND gates with one gate connected to the output of saidinverters and the other gate connected to sgi dpotentiometer taps, aZ-input NAND gate co nnected to the output of said pair of gates andswitching circuits connecting the output of said Z-input NAND gate tosaid motor driven means.

1. A mailing candling apparatus comprising a box having a slot capableof having mail passed therethrough and which slot is defined by bottom,top and side walls, a reversible motor driven means extending acrosssaid slot and capable of moving mail along, a pair of photocells exposedthrough said slot bottom with one before said driven means and one aftersaid driven means, two straight series of photocells exposed throughsaid slot bottom with each series extending laterally of said slotbetween said pair of photocells and with one series positioned beforesaid driving means and the other series positioned after said drivingmeans, means exposed through said slot top for directing light acrosssaid slot to each one of said photoCells, electrical circuit connectedto said pair of photocells capable of operating said motor when mailpasses over either one of said pair of photocells, electrical meansconnecting each opposite pair of photocells of said series of photocellsas sensing circuits connected to said driving means and capable ofreversing said driving means to reject mail from said slot when onesensing circuit creates an off-balance in voltage upon passage of mailwith an enclosure therein.
 2. A mail candling apparatus as claimed inclaim 1 wherein said motor driven means includes a pair of superposedrollers extending between said slot side walls and a reversibleelectrical motor is operatively connected to one of said rollers andsaid electrical circuit and electrical means.
 3. A mail candlingapparatus as claimed in claim 1 wherein said box partially provides saidtop wall and a lid is pivotally con-nected to said box and provides theremainder of said top wall when positioned across said slot.
 4. A mailcandling apparatus as claimed in claim 1 wherein said electrical meansincludes a potentiometer with said two photocells connected thereto andbetween a positive and negative voltage supply in series with saidpotentiometer between said photocells, Zener diodes connected to saidpotentiometer taps, an inverter connected to said diodes, a pair of NANDgates with said inverter connected to one of said gates and saidpotentiometer taps connected to the other of said gates, a further NANDgate connected to the output of said pair of NAND gates and switchingcircuits connecting the output of said further gate to said motor drivenmeans.
 5. A mail candling apparatus as claimed in claim 4 wherein saidelectrical means includes a plurality of potentiometers with eachpotentiometer connected to and between one photocell from each seriesthereof, positive and negative voltage supplies each connected to onephotocell from each series thereof and in series with their respectivepotentiometer, Zener diodes connected to said potentiometer taps,inverters each connected to the diodes of one potentiometer, a pair of4-input NAND gates with one gate connected to the output of saidinverters and the other gate connected to said potentiometer taps, a2-input NAND gate connected to the output of said pair of gates andswitching circuits connecting the output of said 2-input NAND gate tosaid motor driven means.